1. Field of the Invention
The present invention relates to configuring a customer premises network node for network operations with a provider network; and, in particular, to using a network service provider edge node to configure a customer premises node in a communications network without pre-configuring the customer premises node with a network address of a configuration server on the provider network.
2. Description of the Related Art
Networks of general purpose computer systems and other devices connected by external communication links are well known and widely used in commerce. The networks often include one or more network devices that facilitate the passage of information between the computer systems and other devices. A network node is a network device or computer system or other device connected by the communication links.
Information is exchanged between network nodes according to one or more of many well known, new or still developing protocols. In this context, a “protocol” consists of a set of rules defining how the nodes interact with each other based on information sent over the communication links. The protocols are effective at different layers of operation within each node, from generating and receiving physical signals of various types, to selecting a link for transferring those signals, to the format of information indicated by those signals, to identifying which software application executing on a computer system sends or receives the information. The conceptually different layers of protocols for exchanging information over a network are described in the Open Systems Interconnection (OSI) Reference Model. The OSI Reference Model is generally described in more detail in Section 1.1 of the reference book entitled Interconnections Second Edition, by Radia Perlman, published September 1999, which is hereby incorporated by reference as though fully set forth herein.
Communications between nodes are typically effected by exchanging discrete packets of data. Each packet typically comprises 1] header information associated with a particular protocol, and 2] payload information that follows the header information and contains information that may be processed independently of that particular protocol. In some protocols, the packet includes 3] trailer information following the payload and indicating the end of the payload information. The header includes information such as the source of the packet, its destination, the length of the payload, and other properties used by the protocol. Often, the data in the payload for the particular protocol includes a header and payload for a different protocol associated with a different, usually higher layer of the OSI Reference Model. The header for a particular protocol typically indicates a type for the next protocol contained in its payload. The payload protocol is said to be encapsulated in the header protocol. The headers included in a packet traversing multiple heterogeneous networks, such as the Internet, typically include a physical (layer 1) header, a data-link (layer 2) header, an internetwork (layer 3) header and a transport (layer 4) header, as defined by the Open Systems Interconnection (OSI) Reference Model. An end node initiates or terminates a communication, and an intermediate network node facilitates the passage of packets between end nodes.
The physical (layer 1) header defines the electrical, mechanical and procedural mechanisms for proper capture of data on the interface, such as an Ethernet interface, a serial interface for point to point communications, a dial-up interface, a digital subscriber line (DSL) interface, a coaxial cable interface, or an optical fiber interface. A network interface contains the mechanical, electrical and signaling circuitry and logic used to couple a network node to one or more physical links. A network interface is often associated with a hardware-specific address, known as a media access control (MAC) address.
The data-link header provides information for transmitting the packet over a particular link that uses any physical medium. An intermediate network node typically contains multiple physical links with multiple different nodes. To that end, the data-link header may specify a pair of “source” and “destination” network interfaces that are connected by the physical link. Accordingly, the source and destination network interfaces in the data-link header are typically represented as source and destination MAC addresses. The data-link header may also store flow control, frame synchronization and error checking information used to manage data transmissions over the physical link. There are several data link protocols well known in the art, including, but not limited to, Point to Point Protocol (PPP), Frame Relay (FR), Asynchronous Transfer Mode (ATM), High Level Data Link Control (HDLC) and Ethernet.
The internetwork header provides information defining the source and destination address within the computer network. Notably, the path may span multiple physical links. The internetwork header may be formatted according to the Internet Protocol (IP), which specifies IP addresses of both a source and destination node at the end points of the logical path. Thus, the packet may “hop” from node to node along its logical path until it reaches the end node assigned to the destination IP address stored in the packet's internetwork header. After each hop, the source and destination MAC addresses in the packet's data-link header may be updated, as necessary. However, the source and destination IP addresses typically remain unchanged as the packet is transferred from link to link in the network.
In many internetworking scenarios, a local area network (LAN) on one premises of an enterprise, is to be connected to a wide area network (WAN) of a service provider different from the enterprise. The connection is established for any number of reasons. Typical reasons for the connection include obtaining access to the public Internet, and obtaining private access to another LAN at a different premises of the same or a different enterprise. From the service provider's point of view, the enterprise with a LAN is a customer.
The connection involves connecting an intermediate network node on the customer's LAN to an intermediate network node at the edge of the provider's network, a so-called provider edge (PE) node. The intermediate network node on the customer's LAN connected to the PE is the customer premises equipment edge node (designated herein as the CE node).
When a customer determines to connect its LAN to the service provider network, the customer procures a CE with multiple interfaces, some of which are to be connected to nodes on the LAN and one or more of which are for connecting to one or more PE nodes on corresponding WANs. One or more interfaces on the procured CE must be configured for the connections to the PE node and one or more interfaces must be configured for connection to corresponding nodes in the LAN. The configuration data indicates the physical media, the protocols, and the protocol parameter values used to process information at each interface. Configuration data includes the physical access technologies, such as DSL, T1 or Fractional T1 leased lines, access speeds, serial encapsulation type (i.e. FR, PPP, etc.), special services, routing protocols to be used between PE and CE, encryption and other security services enabled on the CE and class of service in terms such as guaranteed minimum bandwidth, minimum latency, and maximum jitter. An example of configuration data includes data that indicates Border Gateway Protocol (BGP) is used between the PE and CE for IP route prefix exchange. The BGP process needs to be explicitly configured on each device with specific parameters such as neighbor IP address, authentication method, Autonomous System Number (ASN) and specific network prefixes to be advertised. All of this unique data for this single CE site is stored locally in the CE's on-board RAM in a “configuration” database after it has been manually input or manually downloaded. In general, the configuration is done by providing values for various options in data read by operating system software that controls the CE. The data can be provided manually or copied from templates of data for different classes of devices that serve as a CE. The selected data values are typically provided by expert network technicians, called system engineers, who understand the needs and topology of the customer LAN as well as the capacities and topology of the provider PEs.
Network service providers have begun to provide CE management services by which the service provider configures the CE for the customer when the customer signs up for the service. Thus, the customer need only connect the CE node device physically to the communications media when the CE node device arrives at the customer premises. The customer can then concentrate on the customer's own core business goals and need not field high levels of network expertise.
A challenge for service providers in providing CE management services is the variability and complexity of customer networking requirements, and the flexibility offered by different hardware and software platforms to serve as the CE node. A single customer is likely to desire different configurations using different platforms at different customer premises.
In one approach, a skilled technician from the service provider accompanies the CE node device to the customer premises and installs and configures the device for the customer This approach is expensive in technician time and travel and introduces delays as devices otherwise ready are not shipped until there are technicians available to accompany them.
In another approach, the CE node device is configured in a staging center before the CE node device is shipped to the customer premises. This allows the high level of network expertise to be concentrated at the staging center, which can be located at the service provider's site, or the site of the vendor or manufacturer for the CE node device used by the service provider. With this approach, a systems engineer is required to provide all the premises-by-premises configuration files to the staging center for installation of configuration data before shipment of the devices.
There are some disadvantages with the staging center approach. One disadvantage is that the staging center is often different from the manufacturing locations, so a device is manufactured, packed and shipped to the staging center. At the staging center, the device is unwrapped, configured, re-packed, and re-shipped to the customer premises. This double handling adds to the delay and the cost of supplying the managed CE node.
Another disadvantage arises when the systems engineer has not completed the final configuration files. In some such cases, the staging process is delayed until the systems engineer completes the determination of the configuration files. In some cases, the CE node device is shipped with a minimal configuration, and a system engineer then follows up with an on-premises visit to complete the configuration. For example, it is common that the virtual circuit identifiers associated with traffic on certain interfaces are not yet allocated in time for the staging process.
Another disadvantage arises when a systems engineer has composed configuration data using a text-editor and has introduced typographical errors. At the staging center, an error or exception will occur. The device is then put aside until the problem can be diagnosed, thus further delaying the delivery of a configured device to the customer premises.
Another disadvantage arises when the device is configured based on erroneous information from the customer. With managed CE node device deployments to large corporations with geographically dispersed premises, it is easy to introduce misinformation about the types and sizes of LANs to be connected to the CE nodes. For example, a device configured for a statically assigned internet protocol (IP) addresses is shipped to a location where the network service provider (SP) expects to assign an IP addresses dynamically. As another example, the SP requires the CE device to connect with Frame Relay protocol but the device is erroneously configured for HDLC Protocol. To deal with such errors, the service provider must dispatch a technician to the customer premises to change the staged configuration.
Another disadvantage arises because a pre-configured device in the staging is not fungible with another device of the same model that is not configured or is configured for a different customer or customer premises. There is an increased chance for an error in which the correctly pre-configured device is shipped to the wrong location or marked for the wrong LAN.
In another approach, a CE node device is configured at a staging center with an internetwork layer address of a configuration server for that customer premises. The configuration server is a host device in the network that can be accessed to retrieve the full configuration file for the CE. This approach suffers from the same delays of double handling experienced by the approach that employs full configuration at the staging center. If multiple configuration servers are used, this approach also suffers the increased chance of shipping the device to the wrong destination for which its configuration server does not have configuration data.
Another disadvantage of this approach is that the configuration server cannot be changed without a manual change to the address of the configuration server, often executed by a visit of a highly skilled technician to the customer premises, and the associated costs.
Based on the foregoing description, there is a clear need for techniques to allow a customer premises edge (CE) node to be physically connected to a wide area network (WAN) and configured automatically through the WAN connection without pre-configuration. More specifically, there is a need for a true plug and play CE node device for use at customer premises.